title: Surface modification of halloysite nanotubes with dopamine for enzyme immobilization.
abstract: Halloysite nanotubes (HNTs) have been proposed as a potential support to immobilize enzymes. Improving enzyme loading on HNTs is critical to their practical applications. Herein, we reported a simple method on the preparation of high-enzyme-loading support by modification with dopamine on the surface of HNTs. The modified HNTs were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analyses. The results showed that dopamine could self-polymerize to adhere to the surface of HNTs and form a thin active coating. While the prepared hybrid nanotubes were used to immobilize enzyme of laccase, they exhibited high loading ability of 168.8 mg/g support, which was greatly higher than that on the pristine HNTs (11.6 mg/g support). The immobilized laccase could retain more than 90% initial activity after 30 days of storage and the free laccase only 32%. The immobilized laccase could also maintain more than 90% initial activity after five repeated uses. In addition, the immobilized laccase exhibited a rapid degradation rate and high degradation efficiency for removal of phenol compounds. These advantages indicated that the new hybrid material can be used as a low-cost and effective support to immobilize enzymes.
authors.affiliation: School of Chemical Engineering, Zhengzhou University , Zhengzhou 450001, People's Republic of China.
authors.forename: Cong
authors.initials: C
authors.lastname: Chao
authors.forename: Jindun
authors.initials: J
authors.lastname: Liu
authors.forename: Jingtao
authors.initials: J
authors.lastname: Wang
authors.forename: Yanwu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Bing
authors.initials: B
authors.lastname: Zhang
authors.forename: Yatao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xu
authors.initials: X
authors.lastname: Xiang
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Chen
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D000077215:Clay; D004298:Dopamine / Q000737:chemistry*; D004800:Enzymes, Immobilized / Q000737:chemistry*; D042845:Laccase / Q000737:chemistry*; D043942:Nanotubes / Q000737:chemistry; D056951:Photoelectron Spectroscopy; D058105:Polymerization; D013499:Surface Properties; D055454:Trametes / Q000201:enzymology
chemical_list: D000538:Aluminum Silicates; D004800:Enzymes, Immobilized; D042845:Laccase; D000077215:Clay; D004298:Dopamine